U.S. patent number 5,716,276 [Application Number 08/706,848] was granted by the patent office on 1998-02-10 for yoke shaft for a vehicular driveshaft assembly.
This patent grant is currently assigned to Dana Corporation. Invention is credited to Eric M. Fischer, Matt J. Mangas.
United States Patent |
5,716,276 |
Mangas , et al. |
February 10, 1998 |
Yoke shaft for a vehicular driveshaft assembly
Abstract
A vehicular driveshaft assembly includes a first universal joint
connected to an aluminum yoke shaft having an externally splined
hollow body. A first open end of an aluminum sleeve receives the
splined body of the yoke shaft. Internal splines of the sleeve
cooperate with the external splines of the yoke shaft body to
permit axial slip between the sleeve and the yoke shaft. A second
end of the sleeve is secured to a first end of a driveshaft tube. A
second end of the driveshaft tube is secured to a tube yoke. The
tube yoke is connected to a second universal joint.
Inventors: |
Mangas; Matt J. (Ft. Wayne,
IN), Fischer; Eric M. (Holland, OH) |
Assignee: |
Dana Corporation (Toledo,
OH)
|
Family
ID: |
24839321 |
Appl.
No.: |
08/706,848 |
Filed: |
September 3, 1996 |
Current U.S.
Class: |
464/16; 464/134;
464/162; 464/173 |
Current CPC
Class: |
F16D
3/845 (20130101); F16C 3/035 (20130101); F16C
3/03 (20130101); F16D 3/06 (20130101); F16D
3/387 (20130101); F16C 2326/06 (20130101) |
Current International
Class: |
F16D
3/02 (20060101); F16D 3/00 (20060101); F16D
3/06 (20060101); F16D 3/84 (20060101); F16C
001/24 (); F16D 003/06 () |
Field of
Search: |
;464/7,16,134,136,157,162,173,175,179,183 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Primary Examiner: Dunn; Eileen A.
Attorney, Agent or Firm: MacMillan, Sobanski & Todd
Claims
What is claimed is:
1. A yoke shaft for use in a vehicular driveshaft assembly
comprising:
a hollow cylindrical body having a closed end, an open end, and an
outer surface having a plurality of splines formed thereon;
a pair of opposed lugs extending from said body;
a plug secured to said body to close said open end so as to define
a chamber within said body; and
a valve mounted in said dosed end of said body to control the flow
of air into and out of said chamber.
2. The yoke shaft defined in claim 1 wherein said body is formed
from aluminum.
3. The yoke shaft defined in claim 1 wherein said body, said lugs,
and said splines are formed from a single piece of material.
4. The yoke shaft defined in claim 1 wherein said plug is a plate
secured to said body to close said open end.
5. The yoke shaft defined in claim 1 wherein said plug is secured
in a recess formed in said body to close said open end.
6. The yoke shaft defined in claim 1 wherein said plug is welded to
said body to close said open end.
7. The yoke shaft defined in claim 1 wherein said plug has an
orifice formed therethrough.
8. A vehicular driveshaft assembly for providing a rotatable
driving connection between an output shaft of a transmission and an
input shaft of an axle assembly, said driveshaft assembly
comprising:
a first universal joint adapted to be connected to the output shaft
of the transmission;
a yoke shaft connected to said first universal joint and including
a hollow cylindrical body having a closed end, an open end, and an
outer surface having a plurality of splines formed thereon, a pair
of opposed lugs extending from said body, a plug secured to said
body to close said open end so as to define a chamber within said
body, and a valve mounted in said closed end of said body to
control the flow of air into and out of said chamber;
a driveshaft tube connected to said yoke shaft for rotational
movement therewith; and
a second universal joint connected to said driveshaft tube and
adapted to be connected to the input shaft of the axle
assembly.
9. The vehicular driveshaft assembly defined in claim 8 wherein
said body is formed from aluminum.
10. The vehicular driveshaft assembly defined in claim 8 wherein
said body, said lugs, and said splines are formed from a single
piece of material.
11. The vehicular driveshaft assembly defined in claim 8 wherein
said plug is a plate secured to said body to close said open
end.
12. The vehicular driveshaft assembly defined in claim 8 wherein
said plug is secured in a recess formed in said body to close said
open end.
13. The vehicular driveshaft assembly defined in claim 8 wherein
said plug is welded to said body to close said open end.
14. The vehicular driveshaft assembly defined in claim 8 wherein
said plug has an orifice formed therethrough.
15. The vehicular driveshaft assembly defined in claim 8 wherein
said driveshaft tube is connected to said yoke shaft for axial
movement relative thereto.
Description
BACKGROUND OF THE INVENTION
This invention relates in general to vehicular driveshaft
assemblies for transferring power in a vehicle, and in particular
to an improved yoke shaft for transferring torque and permitting
axial slip in a driveshaft assembly.
In many different types of vehicles, a driveshaft assembly is
utilized to transmit rotational power from a source, such as an
engine, to a driven component, such as a pair of wheels. A typical
vehicular driveshaft assembly provides a rotational driving
connection between an output shaft of a vehicular transmission and
an input shaft of an axle assembly, while permitting a limited
about of relative axial movement therebetween. This axial movement
is commonly referred to as "axial slip".
A transmission is connected to the engine to provide desired gear
ratios through which engine power is delivered to the wheels. The
transmission has an output shaft connected through an elongated
driveshaft assembly to an input shaft of an axle assembly. Because
of constraints imposed by the overall design of the vehicle, these
shafts are rarely aligned such that their axes of rotation are
co-axial. Therefore, universal joints are provided between the
transmission output shaft and the forward end of the driveshaft
assembly and between the rearward end of the driveshaft assembly
and the axle assembly input shaft. The universal joints permit the
axes of rotation of the adjacent shafts to be angularly disposed,
while providing a rotational driving connection therebetween.
A conventional driveshaft assembly includes a forward steel slip
yoke connected through a forward universal joint and an aluminum
driveshaft tube to a rearward universal joint connected to an axle
assembly. The forward steel slip yoke has a forwardly extending
hollow portion which is internally splined to cooperate with a male
splined output shaft from the transmission. Thus, axial slip is
accommodated outboard of the end of the driveshaft assembly. In a
second conventional driveshaft assembly, a forward universal joint
is connected through a forward steel slip yoke and a steel
driveshaft tube to a rearward universal joint connected to the axle
assembly. The forward end of the driveshaft tube has a forwardly
extending male splined portion which cooperates with an internally
splined portion of the slip yoke connected to the forward universal
joint. Thus, axial slip is accommodated inboard of the end of the
driveshaft assembly. A third conventional driveshaft assembly
includes a forward universal joint connected through a forward
steel yoke shaft and a steel driveshaft tube to a rearward
universal joint connected to the axle assembly. The forward end of
the driveshaft tube has a forwardly extending internally splined
hollow portion which cooperates with the externally splined, solid
cylindrical male portion of the forward yoke shaft connected to the
forward universal joint. Thus, axial slip is accommodated inboard
of the end of the driveshaft assembly.
SUMMARY OF THE INVENTION
This invention relates to a lightweight and durable vehicular
driveshaft assembly. This invention further contemplates a yoke
shaft formed from aluminum or an aluminum alloy having splines
mated with splines of an aluminum sleeve to transmit rotational
power. Axial slip in a driveshaft assembly utilizing this yoke
shaft is provided as the yoke shaft slides with respect to the
sleeve. Thus, axial slip is accommodated inboard of the end of such
a driveshaft assembly. Such a driveshaft assembly provides reduced
weight and higher critical speed when compared to known driveshaft
assemblies.
In a preferred embodiment, a vehicular driveshaft assembly includes
a first universal joint connected to an aluminum yoke shaft having
an externally splined hollow body. A first open end of an aluminum
sleeve receives the splined body of the yoke shaft. Internal
splines of the sleeve cooperate with the external splines of the
yoke shaft body to permit axial slip between the sleeve and the
yoke shaft. A second end of the sleeve is secured to a first end of
a driveshaft tube. A second end of the driveshaft tube is secured
to a tube yoke. The tube yoke is connected to a second universal
joint.
Various objects and advantages of this invention will become
apparent to those skilled in the art from the following detailed
description of the preferred embodiment, when read in light of the
accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is an axial sectional view of a yoke shaft in accordance
with this invention.
FIG. 2 is a sectional view taken along line 2--2 of FIG. 1.
FIG. 3 is an elevational view, partly in axial section, of a
vehicular driveshaft incorporating the yoke shaft of FIGS. 1 and
2.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring now to the drawings, there is illustrated in FIG. 1 a
yoke shaft assembly, indicated generally at 10, according to this
invention. The yoke shaft assembly 10 includes a yoke shaft
indicated generally at 12, a valve 14 and a plug 16.
The yoke shaft 12 is a hollow cylindrical member including a first
or forward end 18 having a pair of opposed, axially extending lugs
20a, 20b. Each lug 20a, 20b projects forwardly (to the left as
viewed in FIG. 1) away from the remainder of the yoke shaft 12.
Preferably, the lugs 20a, 20b are substantially parallel to a
longitudinal axis 22 of the yoke shaft 12. An opening 24a, 24b is
provided in each of the lugs 20a, 20b, respectively. The openings
24a, 24b are aligned with one another.
The first end 18 closes a forward end of a hollow central body 26.
A second or rearward end 28 of the central body 26 is open. At
least one radially outwardly extending spline 30 is formed on an
outer surface of the central body 26. Preferably, a plurality of
splines 30 are formed about the circumference of the central body
26 as illustrated in FIG. 2. Preferably, each spline 30 originates
adjacent the second end 28 and extends axially along the outer
surface of the central body 26 a predetermined distance.
Preferably, each spline 30 is parallel to the axis 22 and does not
extend radially beyond an outer diameter formed by the lugs 20a,
20b. To reduce friction, the splines 30 are coated with a
lubricant, preferably a lubricant containing nylon. A lubricant
containing nylon enhances the surface of the splines 30 such than
desirable manufacturing tolerances can be achieved.
Preferably, the yoke shaft 12 is an integrally formed, one-piece
member which can be manufactured in any desired manner. For
example, the yoke shaft 12 can be formed as a casting from a
suitable material and machined as desired to form the openings 24a,
24b, the splines 30, and the like. Preferably a lightweight
material such as aluminum is used for the yoke shaft 12. For
purposes of this description, the use of aluminum as a preferred
material also includes the use of aluminum alloys. When a material
such as aluminum is used for the yoke shaft 12, the diameter of the
central body 26 is generally larger than the diameter of a central
body formed from a material such as steel. This larger diameter
provides additional strength to resist stresses incurred by the
yoke shaft 12 when installed as part of a vehicular driveshaft
assembly.
The valve 14 is mounted in a central opening 32 formed in the
closed end 18. The valve 14 controls the flow of air into and out
of a chamber 34 formed in the interior volume of the central body
26 as the yoke shaft 12 slides axially in a vehicular driveshaft
assembly as described below. The plug 16 includes a central orifice
36 and is secured in an interior recess 38 by welding or the like.
The plug 16 retains lubricant and prevent debris from reaching the
chamber 34.
A vehicular driveshaft assembly is indicated generally at 100 in
FIG. 3. The driveshaft assembly 100 includes the yoke shaft
assembly 10 illustrated in FIGS. 1 and 2 and transmits rotational
power from an output shaft of a transmission indicated
schematically at 102 to an input shaft of an axle assembly
indicated schematically at 104. A first or forward universal joint
assembly 106 (left end as viewed in FIG. 3) connects the assembly
100 to the transmission 102. A second or rearward universal joint
assembly 108 (right end as viewed in FIG. 3) connects the assembly
100 to the axle assembly 104.
A hollow cylindrical sleeve 110 includes internal splines 112 mated
to the splines 30 of the yoke shaft 12. The internal splines 112
extend axially along an inner surface of a forward end of the
sleeve 110. Preferably, the splines 112 are coated with a
lubricant, particularly a grease to reduce friction. The mated
splines 112 and 30 transfer rotational movement from the yoke shaft
12 (delivered from the transmission 102) to the sleeve 110.
Simultaneously, the mated splines 112 and 30 permit a predetermined
amount of axial slip between the yoke shaft 12 and the sleeve 110.
To reduce weight of the assembly 100, the sleeve 110 is preferably
formed from a lightweight material such as aluminum or an aluminum
alloy.
A reduced outer diameter neck 114 is formed at the rearward end of
the sleeve 110. The neck 114 is press fitted into an open forward
end of a hollow driveshaft tube 116. At this intersection, the
sleeve 110 and driveshaft tube 116 are secured together by welding,
adhesive, or other suitable means. Preferably, the driveshaft tube
116 is formed from a lightweight material such as aluminum or an
aluminum alloy.
A tube yoke 118 includes a forwardly extending tube seat 120 press
fitted into an open rearward end of the driveshaft tube 116. The
tube yoke 118 and the driveshaft tube 116 are secured together by
welding, adhesive or other suitable means, thereby enabling torque
to be transmitted between the driveshaft tube 116 and the tube yoke
118. Preferably, the tube yoke 118 is formed from a lightweight
material such as aluminum or an aluminum alloy. Lugs 122a, 122b
formed on the rearward end of the tube yoke 118 receive the
rearward universal joint assembly 108 in a well-known manner.
A flexible boot 124 is attached at a first end by a retainer 126 to
the central body 26 of the yoke shaft 12. A second end of the boot
124 is attached by a retainer 128 to a forward end of the sleeve
110. The boot 124 prevents contaminants from reaching the splines
112 and 30 and expands and contracts as the yoke shaft 12 and
sleeve 110 slide with respect to one another.
The driveshaft assembly 100 provides a lightweight connection
between the transmission 102 and the axle assembly 104. In a
preferred embodiment of the assembly 100, the yoke shaft 12, sleeve
110, driveshaft tube 116 and tube yoke 118 are formed from a
lightweight material such as aluminum or an aluminum alloy.
Furthermore, the plug 16 is formed from aluminum or an aluminum
alloy. In use, axial slip in the assembly 100 is provided as the
yoke shaft 12 slides with respect to the sleeve 110. This axial
slip is accommodated inboard of the end of the assembly 100. The
assembly 100 provides reduced weight and higher critical speed when
compared to known driveshaft assemblies.
A preferred embodiment of the assembly 100 includes male splines 30
on the outer surface of the yoke shaft 12 which have been coated
with a nylon lubricant, while the female splines 112 of the sleeve
110 are coated with a grease. In another embodiment, female splines
112 can also be coated with a nylon lubricant and grease can be
used between the splines 30 and 112. In yet other embodiment, only
the female splines 112 can be coated with a nylon lubricant, while
a grease is applied to the male splines 30.
In accordance with the provisions of the patent statutes, the
principle and mode of operation of this invention have been
explained and illustrated in its preferred embodiment. However, it
must be understood that this invention may be practiced otherwise
than as specifically explained and illustrated without departing
from its spirit or scope.
* * * * *